1. Field of the Invention
The present invention relates to an information record medium such as an optical disk of a high recording density type, which is capable of recording information such as video information, audio information and the like at a high density, and which is represented by a DVD (Digital Video or Versatile Disk). The present invention also relates to a recording apparatus for recording the information onto the information record medium, and a reproducing apparatus for reproducing the information from the information record medium.
2. Description of the Related Art
Conventionally, a so-called LD (Laser Disk) and a so called CD (Compact Disk) are generalized as optical disks, on which information such as video information, audio information and the like is recorded.
On the LD or the like, the video information and the audio information are recorded together with time information indicating a time at which each information is to be reproduced with respect to a reproduction start position, which each LD or the like has, as a standard position. Thus, other than a general normal reproduction to reproduce the recorded information in the order of recording, various special reproductions are possible, such as a reproduction to extract and listen to an only desirable music out of a plurality of recorded musics, a reproduction to listen to the recorded musics in a random order and so on, in case of the CD, for example.
However, there is a problem that, according to the above mentioned LD or the like, a so called interactive and variegated reproduction is not possible in which the audience can have a plurality of selection branches as for the video or audio information to be displayed or sound outputted and in which the audience can select them to watch or listen to it.
Namely, for example, in case of giving audience to a foreign movie on the LD, it is not possible to select one of languages to be used for a subtitle (caption) displayed on the picture plane (e.g., select one of the subtitle in Japanese and the subtitle in the original language) so as to display the subtitle in the selected language, or, in case of giving audience to a music recorded on the CD, it is not possible to select one of sound voices of the music (e.g., select one of the English lyric and the Japanese lyric).
On the other hand, various proposals and developments are being made as for the DVD, as an optical disk in which the memory capacity is improved by about ten times without changing the size of the optical disk itself as compared with the aforementioned conventional CD. With respect to this DVD, if a plurality of subtitles in various languages or a plurality of voice sounds in various languages are recorded, the above mentioned interactive and variegated reproduction is possible as the audience selects one of them.
When recording the audio voices in a plurality of different languages, various kinds of musics and the like on the DVD, it is possible to increase the number of bits at a time of digitizing and recording them to thereby record the audio sound and the like with high quality. However, at this time, if trying to make the reproducing apparatus cheaper by utilizing a decoder used in the conventional reproducing apparatus, there may be a case where the decoder does not have a processing capacity corresponding to the number of the bits of the audio sound and the like recorded on the DVD.
In this case, unless the audio sound or the like is recorded in an appropriate recording condition, there may occur a problem that the audio information to be reproduced cannot be reproduced at a time of reproducing by using the cheap reproducing apparatus in which the conventional decoder is utilized.